From the beginning of 50th there was a rise of migrants studies until the mid 1970. The main reason for this phenomenon - funding available, for understanding the interaction between host and environment. The methodology died with the beginning of using the case-control studies. Migrant studies took a very big time for full-filling a study. Migrant studies concluded: environment plays a role - that it! Big! But what is environment effect? At 1965 scientists prove the environmental reasons for diabetes, cardiovascular diseases, cancer. Now we are interesting with integration of environmental effects with molecular biology.